Voltage control method, device, household appliance and computer storage medium

Abstract

The present application discloses a voltage control method, device, household appliance, and computer storage medium. The method includes: obtaining two half-bus voltages on the DC side of a three-level converter, overvoltage protection values ​​of the two half-bus voltages, and a voltage required by a first load, where the first load represents a load supplied with a voltage equal to any one of the two half-bus voltages; determining a voltage control strategy based on the relationship between the two half-bus voltages, the overvoltage protection value, and the voltage required by the first load; the voltage control strategy is used to compensate for the output duty cycle of the switching devices of the three-level converter so that the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value; the first half-bus voltage represents the half-bus voltage supplying power to the first load; and voltage control is performed on the two half-bus voltages according to the voltage control strategy.

Description

Technical Field

[0001] The embodiments of the present application belong to the field of power supply control, and in particular relate to a voltage control method, device, household appliance, and computer storage medium. Background Art

[0002] Currently, power factor correction (PFC) technology has been widely used. In related technologies, the control scheme for a three-level, three-phase active PFC circuit generally adopts midpoint balancing control to make the upper half bus voltage equal to the lower half bus voltage to control the half bus voltage. However, in this control scheme, when one of the half bus voltages is loaded, the output duty cycle will have a larger positive and negative deviation, resulting in a greater imbalance in the positive and negative half waveforms of the input current and a certain increase in current harmonics. Summary of the Invention

[0003] The embodiments of the present application provide a voltage control method, device, household appliance and computer storage medium, which can solve the problems in the related art of greater imbalance in the waveforms of the positive and negative halves of the input current and larger current harmonics.

[0004] The technical solution of the embodiment of the present application is implemented as follows:

[0005] An embodiment of the present application provides a voltage control method, which is applied to a PFC circuit, wherein the PFC circuit includes a three-level converter. The method includes:

[0006] Obtaining two half-bus voltages on the DC side of the three-level converter, overvoltage protection values ​​of the two half-bus voltages, and a voltage required by a first load; the first load represents a load whose supply voltage is any one of the two half-bus voltages;

[0007] determining a voltage control strategy based on a relationship between the two half-bus voltages, the overvoltage protection value, and a voltage required by the first load; the voltage control strategy being configured to compensate for an output duty cycle of a switching device of the three-level converter so that the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value; the first half-bus voltage representing a half-bus voltage supplying power to the first load;

[0008] The two half-bus voltages are controlled according to the voltage control strategy.

[0009] An embodiment of the present application further provides a voltage control device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any one of the above methods when executing the program.

[0010] An embodiment of the present application also provides a household appliance, which includes the above-mentioned voltage control device and a second load; the voltage control device is connected between the AC power supply signal and the second load, and the voltage control device is configured to control the AC power supply signal to supply power to the second load.

[0011] An embodiment of the present application also provides a computer storage medium on which one or more programs are stored. The one or more programs can be executed by one or more processors to implement any of the above methods.

[0012] An embodiment of the present application provides a voltage control method, device, household appliance and computer storage medium, the method comprising: obtaining two half-bus voltages on the DC side of the three-level converter, overvoltage protection values ​​of the two half-bus voltages and a voltage required by a first load, wherein the first load represents a load whose supply voltage is any one of the two half-bus voltages; determining a voltage control strategy based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load; the voltage control strategy is used to compensate for the output duty cycle of the switching device of the three-level converter so that the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value; the first half-bus voltage represents the half-bus voltage supplying power to the first load; and voltage control is performed on the two half-bus voltages according to the voltage control strategy.

[0013] It can be seen that the embodiment of the present application can adjust the two half-bus voltages according to the overvoltage protection value and the voltage required by the first load to limit the normal variation range of the two half-bus voltages, thereby facilitating normal operation of the load. Since there is no need to use midpoint balancing control to make the upper half-bus voltage equal to the lower half-bus voltage to control the half-bus voltage, the problem of greater imbalance in the waveforms of the positive and negative halves of the input current can be alleviated to a certain extent, and current harmonics can be improved, thereby increasing the stability of the PFC circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A A schematic diagram of a topological structure of a three-phase active PFC circuit in an embodiment of the present application;

[0015] Figure 1B Schematic diagram of another topology structure of a three-phase active PFC circuit in an embodiment of the present application;

[0016] Figure 2A A schematic diagram of a combination of power switch devices in an embodiment of the present application;

[0017] Figure 2B Schematic diagram of another combination of power switch devices in an embodiment of the present application;

[0018] Figure 2C This is a schematic diagram of another combination of power switch devices in an embodiment of the present application;

[0019] Figure 3 This is an optional structural diagram of a three-phase active PFC circuit according to an embodiment of the present application;

[0020] Figure 4 This is a flow chart of a voltage control method according to an embodiment of the present application;

[0021] Figure 5 This is a schematic diagram of a control model of a three-phase three-level rectifier module in an embodiment of the present application;

[0022] Figure 6 This is a flowchart of compensating the output duty cycle of a switching device in an embodiment of the present application;

[0023] Figure 7 This is a flow chart of determining the control amount of the half bus voltage in an embodiment of the present application;

[0024] Figure 8 Schematic diagram of the structure of the voltage control device according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0026] The embodiments of the present application can be applied to a PFC circuit, which can be used to power a load of a household appliance. Here, the household appliance can be an electrical appliance such as a refrigerator, an air conditioner, and a rice cooker. The PFC circuit can be, for example, a three-phase active PFC circuit.

[0027] Figure 1A and Figure 1B Schematic diagram of two topological structures of the three-phase active PFC circuit in the embodiment of the present application, refer to Figure 1A and Figure 1B , Va, Vb and Vc represent the input voltage of three-phase alternating current respectively, ia, ib and ic represent the input three-phase current respectively, and three-phase alternating current represents three electrical signals with the same frequency, equal potential amplitude and a phase difference of 120°.

[0028] In the embodiment of the present application, the input three-phase currents ia, ib and ic can be rectified by a three-level converter, referring to Figure 1A and Figure 1B The three-level converter may include three bidirectionally conductive power switch device combinations Sa, Sb, and Sc, where Sa, Sb, and Sc represent power switch device combinations corresponding to ia, ib, and ic, respectively. Exemplarily, the power switch devices in the power switch device combinations may be metal-oxide-semiconductor field-effect transistors (MOS) made of silicon (Si) material, or insulated gate bipolar transistors (IGBT) devices, or may be MOS devices made of silicon carbide (SiC) material or MOS devices made of gallium nitride (GaN). The embodiments of the present application are not limited to this.

[0029] For example, the combination of power switching devices can be Figure 1A and Figure 1B The form shown can also be Figures 2A to 2C The combination shown is not limited in the embodiments of the present application.

[0030] In the embodiment of the present application, the two half bus voltages on the DC side of the three-level converter include an upper half bus voltage and a lower half bus voltage. Figure 1A and Figure 1B , the first capacitor C on the DC side of the three-level converter bus+ is the upper half bus capacitance, the first capacitor C bus+ The voltage across the two ends is the upper half bus voltage, and the second capacitor C on the DC side of the three-level converter bus- is the lower half bus capacitance, the second capacitor C bus- The voltage across both ends is the lower half bus voltage.

[0031] The first capacitor C bus+ and the second capacitor C bus- The voltage across the branch of the group leader is the full bus voltage, which can also be simply referred to as the bus voltage. For example, the upper half bus voltage or the lower half bus voltage is half the bus voltage. It is understood that the remaining unknown voltage value can be derived based on any two known voltage values ​​among the upper half bus voltage, the lower half bus voltage, and the bus voltage.

[0032] For example, the first capacitor C bus+ and the second capacitor C bus- It can be an electrolytic capacitor or other types of capacitors.

[0033] It is understood by those skilled in the art that the bus voltage, the upper half bus voltage, and the lower half bus voltage can be regarded as the power supply voltage to the load. In some embodiments, the power supply signal can be an AC power supply signal of the mains. In other embodiments, the power supply signal can be a reference signal. Figure 1A and Figure 1B , the power supply signal may also be a DC power supply signal rectified by a three-level converter.

[0034] During their research into three-phase active PFC circuits, the inventors discovered that related art typically employs midpoint balancing control to equalize the upper and lower bus voltages to control the half-bus voltages. However, this approach results in a greater positive and negative deviation in the output duty cycle, causing a significant imbalance in the waveforms of the positive and negative halves of the input current. This impacts the stability of the three-phase active PFC circuit and increases current harmonics. Furthermore, this approach exacerbates the power imbalance between the upper and lower bus capacitors.

[0035] In view of the above technical problems, the present application is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the embodiments provided herein are merely for explaining the present application and are not intended to limit the present application. In addition, the embodiments provided below are partial embodiments for implementing the present application, rather than providing all embodiments for implementing the present application. In the absence of conflict, the technical solutions described in the present application may be implemented in any combination.

[0036] It should be noted that, in this application, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method or apparatus comprising a series of elements includes not only the elements explicitly stated, but also other elements not explicitly listed, or also includes elements inherent to the implementation of the method or apparatus. In the absence of further restrictions, an element defined by the phrase "comprising a ..." does not exclude the presence of other related elements (such as steps in the method or units in the apparatus, for example, a unit may be part of a processor, part of a program or software, etc.) in the method or apparatus comprising the element.

[0037] The term "and / or" herein simply describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of three situations: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0038] For example, the voltage control method provided in the embodiment of the present application includes a series of steps, but the voltage control method provided in the embodiment of the present application is not limited to the recorded steps. Similarly, the voltage control device provided in the embodiment of the present application includes a series of modules, but the voltage control device provided in the embodiment of the present application includes the modules that are clearly recorded, and may also include modules that need to be set up to obtain relevant information or perform processing based on information.

[0039] The embodiments of the present application can be implemented based on a voltage control device, which can include a program module for executing computer system instructions. The computer system can be implemented in a distributed cloud computing environment. In a distributed cloud computing environment, the program module can be located on a local or remote computing system storage medium, including a storage device.

[0040] The embodiment of the present application provides a voltage control method that can be applied to a PFC circuit. In the case where the PFC circuit is a three-phase active PFC circuit, the three-phase active PFC circuit of the embodiment of the present application can be combined with Figure 3 For explanation, refer to Figure 3 The three-phase active PFC circuit may include an input power module 301 , a three-phase three-level rectifier module 302 , a load 1 , and a load 2 .

[0041] The input power module 301 is used to input three-phase current to the three-phase three-level rectifier module 302. Figure 3 The meanings of Va, Vb, Vc, ia, ib and ic have been explained in the above description and will not be repeated here.

[0042] Exemplarily, the three-phase three-level rectifier module 302 can be a T-type three-level converter, and the topology of the three-phase three-level rectifier module 302 can be a Vienna topology. The three-phase three-level rectifier module 302 is used to convert an AC signal into a DC signal; the three-phase three-level rectifier module 302 also includes a first inductor L1, a second inductor L2, and a third inductor L3.

[0043] In the three-phase three-level rectifier module 302, the third capacitor C1 is the upper half bus capacitor, the fourth capacitor C2 is the lower half bus capacitor, and the voltage across the third capacitor C1 is the upper half bus voltage V bus_p , the voltage across the fourth capacitor C2 is the lower half bus voltage V bus_n .

[0044] The supply voltage of load 1 is the lower half bus voltage V bus_n , that is, load 1 is a half-bus voltage load; the supply voltage of load 2 is the bus voltage V0, that is, load 2 is a full bus voltage load.

[0045] It should be noted that, in actual scenarios, load 1 or load 2 may be an optional load, that is, illustratively, the load of the three-phase active PFC circuit may include load 1 and load 2, or may be load 1 or load 2.

[0046] For example, for Figure 3 The three-phase active PFC circuit shown in FIG can also be equipped with a voltage and current acquisition module ( Figure 3 (not shown); in one implementation, the voltage and current acquisition module is used to collect at least two-phase input currents, at least two input phase voltages or line voltages, and at least two bus voltages (i.e., at least two of the bus voltage, the upper half bus voltage, and the lower half bus voltage); in another implementation, the voltage and current acquisition module is used to collect three-phase input currents, three input phase voltages, the bus voltage, the upper half bus voltage, and the lower half bus voltage.

[0047] It should be noted that Figure 1A 、 Figure 1B and Figure 3 The circuit structures shown are only several exemplary circuit structures in the embodiments of the present application. The application scenarios of the voltage control method in the embodiments of the present application are not limited to Figure 1A 、 Figure 1B and Figure 3 The circuit structure shown.

[0048] Figure 4 This is a flow chart of a voltage control method provided in an embodiment of the present application. The voltage control method can be applied to a PFC circuit, such as Figure 4 As shown, the process may include:

[0049] Step 401: Obtain two half-bus voltages on the DC side of a three-level converter, overvoltage protection values ​​of the two half-bus voltages, and a voltage required by a first load, where the first load is a load whose supply voltage is any one of the two half-bus voltages.

[0050] In an embodiment of the present application, the two half-bus voltages on the DC side of the three-level converter include the above-mentioned upper half-bus voltage and lower half-bus voltage; illustratively, the two half-bus voltages on the DC side of the three-level converter can be obtained by voltage detection.

[0051] Exemplarily, the overvoltage protection value of the two and a half bus voltages may represent the upper limit that the two and a half bus voltages are allowed to reach, and the overvoltage protection value of the two and a half bus voltages may be set according to actual needs.

[0052] Exemplarily, the overvoltage protection values ​​of the two half-bus voltages may be the same or different.

[0053] In the embodiment of the present application, the first load may represent a load when the supply voltage is the upper half bus voltage or the lower half bus voltage. For example, the first load may be Figure 3 Load 1 in.

[0054] In an embodiment of the present application, the voltage required by the first load represents the minimum supply voltage required to drive the first load to operate normally. The voltage required by the first load can be obtained from the operating parameters of the first load. The operating parameters of the first load can be predetermined parameters; for example, the voltage required by the first load is 50V or 60V.

[0055] Step 402: Determine a voltage control strategy according to the relationship between the two half-bus voltages, the overvoltage protection value, and the voltage required by the first load.

[0056] The voltage control strategy is used to compensate for the output duty cycle of the switching devices of the three-level converter so that the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value; the first half-bus voltage represents the half-bus voltage that supplies power to the first load.

[0057] In the embodiment of the present application, the output duty cycle of the switching device represents the proportion of the on-time of the switching device to the total time within a pulse cycle.

[0058] Exemplarily, when the overvoltage protection values ​​of the two half-bus voltages are the same, the voltage control strategy is used to compensate the output duty cycle of the switching device of the three-level converter so that each of the two half-bus voltages is less than or equal to the common overvoltage protection value.

[0059] Exemplarily, when the overvoltage protection values ​​of the two half-bus voltages are different, the voltage control strategy is used to compensate the output duty cycle of the switching device of the three-level converter so that each of the two half-bus voltages is less than or equal to its corresponding overvoltage protection value.

[0060] Exemplarily, the above-mentioned overvoltage protection value is less than or equal to the withstand voltage value of the capacitor on the DC side of the three-level converter; exemplarily, when the capacitor on the DC side of the three-level converter is an electrolytic capacitor, a certain margin can be subtracted based on the withstand voltage value of the electrolytic capacitor. For example, when the withstand voltage value of the capacitor on the DC side of the three-level converter is 450V, the overvoltage protection value can be (450-N)V, where N is a positive number between 0 and 100.

[0061] It can be understood that when the overvoltage protection value is less than or equal to the withstand voltage value of the capacitor on the DC side of the three-level converter, the half-bus voltage can be controlled by the voltage control strategy, so that the half-bus voltage can be less than or equal to the withstand voltage value of the capacitor on the DC side of the three-level converter, thereby making the capacitor on the DC side of the three-level converter in normal operation.

[0062] In an embodiment of the present application, the two half-bus voltages can be adjusted according to the overvoltage protection value and the voltage required by the first load to limit the normal variation range of the two half-bus voltages. As long as the two half-bus voltages are within the normal variation range, the operating state of the load can be improved; illustratively, the adjustment of the two half-bus voltages can be achieved by adjusting the output duty cycle of the switching device.

[0063] Step 403: Perform voltage control on the two half-bus voltages according to the voltage control strategy.

[0064] In practical applications, the above steps 401 to 403 can be implemented by a processor in the voltage control device, and the above processor can be at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a central processing unit (CPU), a controller, a microcontroller, and a microprocessor.

[0065] In the voltage control method provided in an embodiment of the present application, first, the two half-bus voltages on the DC side of the three-level converter, the overvoltage protection values ​​of the two half-bus voltages, the voltage required by the first load, and the voltage required by the full bus load are obtained; then, a voltage control strategy is determined; the voltage control strategy is used to compensate for the output duty cycle of the switching device of the three-level converter so that the full bus voltage load is satisfied (that is, the full bus voltage is greater than or equal to the full bus voltage load), and the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value; finally, the two half-bus voltages are voltage-controlled according to the voltage control strategy. It can be seen that the embodiment of the present application can adjust the two half-bus voltages according to the overvoltage protection value and the voltage required by the first load to limit the normal variation range of the two half-bus voltages, thereby facilitating improvement of the operating state of the load; since there is no need to adopt midpoint balancing control to make the upper half-bus voltage equal to the lower half-bus voltage to control the half-bus voltage, the problem of significant imbalance in the waveforms of the positive and negative halves of the input current can be alleviated to a certain extent, and current harmonics can be improved, the power imbalance between the upper half-bus capacitor and the lower half-bus capacitor can be alleviated, and the stability of the PFC circuit can be improved.

[0066] Exemplarily, the above-mentioned determination of the voltage control strategy based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may include: determining the output duty cycle compensation amount based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load, and using the output duty cycle compensation amount to compensate for the current output duty cycle of the switching device.

[0067] In an embodiment of the present application, the initial value of the output duty cycle of the switching device can be pre-set according to actual needs. After determining the initial value of the output duty cycle of the switching device, the current output duty cycle of the switching device can be continuously adjusted according to the output duty cycle compensation amount until the first half-bus voltage is greater than or equal to the voltage required by the first load, and each of the two half-bus voltages is less than or equal to the overvoltage protection value.

[0068] In one implementation, the output duty cycle compensation amount can be a positive value or a negative value; in one implementation, when determining the output duty cycle compensation amount, the output duty cycle compensation amount can be added to the current output duty cycle of the switching device to adjust the output duty cycle of the switching device.

[0069] It can be understood that the output duty cycle compensation amount is determined based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load, and then the current output duty cycle of the switching device is compensated. Therefore, by compensating the current output duty cycle of the switching device, it is beneficial to make the first half-bus voltage greater than or equal to the voltage required by the first load, and to make each of the two half-bus voltages less than or equal to the overvoltage protection value.

[0070] The following combination Figure 5 The implementation process of the voltage control method of the embodiment of the present application is described.

[0071] Figure 5 This is a schematic diagram of the control model of the three-phase three-level rectifier module in the embodiment of the present application, referring to Figure 5 The input of the control model of the three-phase three-level rectifier module includes the upper half bus voltage V bus_p , lower half bus voltage V bus_n , full bus voltage V0, three-phase AC input voltage Vi (including Va, Vb and Vc), and input three-phase current (ia, ib and ic).

[0072] Reference Figure 5 The control model of the three-phase three-level rectifier module includes a phase locked loop (PLL) 501, which is used to obtain a voltage phase θ according to the input voltage of the three-phase alternating current. The voltage phase θ is input to the coordinate transformation module (dq2abc) 502 of the control model of the three-phase three-level rectifier module.

[0073] The dq2abc 502 is used to convert the current or voltage in the three-phase static coordinate system into the current or voltage in the dynamic coordinate system according to the voltage phase θ.

[0074] The control model of the three-phase three-level rectifier module can also include a voltage loop, refer to Figure 5 The voltage loop outputs the current command i according to the target full bus voltage V0* and the input actual full bus voltage V0 through the proportional integral (PI) controller. d * to the current loop.

[0075] The control model of the three-phase three-level rectifier module can also include a current loop, refer to Figure 5 The current loop is used to calculate the current command i d *、Current instruction i q * and the current in the dynamic coordinate system output by dq2abc 502 (including i d and i q), perform PI control, and the output result after PI control is the voltage (including V sd and V sq ) to decouple and obtain the voltage command V rd and V rq , according to the voltage command V rd and V rq And the actual full bus voltage V0 of the input is used to calculate the duty cycle d in the moving coordinate system d and d q , and the duty cycle d in the mobile coordinate system d and d q The output is sent to the Space Vector Pulse Width Modulation (SVPWM) module 503 .

[0076] For example, the current command i q * can be a preset fixed value, for example, the current command i q * is 0.

[0077] Reference Figure 5 The SVPWM module 503 is used to convert the duty cycle d in the moving coordinate system into d The three-phase output duty cycle is converted into dq, and the converted three-phase output duty cycle is compensated according to the output duty cycle compensation r output by the half-bus voltage control module 504 to obtain the final output duty cycle d for output to the switching device 505. a d b and d c .

[0078] Reference Figure 5 The half-bus voltage control module 504 is used to generate an output duty cycle compensation value r according to the method described in the above embodiment.

[0079] Exemplarily, the above-mentioned determination of the output duty cycle compensation amount based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may include: determining the control amount of the half-bus voltage based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load; and performing PI control on the control amount of the half-bus voltage to obtain the output duty cycle compensation amount.

[0080] In the embodiment of the present application, the control quantity of the half-bus voltage can be a voltage value. By performing PI control on the control quantity of the half-bus voltage, the voltage value can be converted into an output duty cycle compensation amount.

[0081] It can be understood that by performing PI control on the control amount of the half-bus voltage, the duty cycle compensation amount can be obtained relatively easily.

[0082] The following combination Figure 6 The process of compensating the output duty cycle of a switching device is described.

[0083] Figure 6 The input of the feedback voltage control module 601 includes the voltage V Ld1 , upper half bus voltage V bus_p , lower half bus voltage V bus_n and the overvoltage protection value V of the two half bus voltages lim .

[0084] Feedback voltage control module 601 is used to obtain the control value V of the half bus voltage according to the input value bus_fb .

[0085] The input of the duty cycle compensation controller 602 includes the control quantity V bus_fb The duty cycle compensation controller 602 is used to control the half bus voltage V bus_fb Perform PI control to obtain the output duty cycle compensation r. Here, the output duty cycle compensation r is used to compensate the output duty cycle d of the SVPWM module 503 to obtain the compensated output duty cycle d', which may include the above-mentioned output duty cycle d a d b and d c In practical applications, through Figure 6 The process shown in the figure continuously compensates the output duty cycle d of the SVPWM module 503, so that the control amount V bus_fb Approaching 0.

[0086] Exemplarily, the above-mentioned determination of the control amount of the half-bus voltage based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may include: determining that the two half-bus voltages are both less than or equal to the overvoltage protection value, judging the relationship between the first half-bus voltage and the voltage required by the first load, and obtaining a judgment result; and determining the control amount of the half-bus voltage based on the judgment result.

[0087] It can be understood that the embodiment of the present application can determine the control amount of the half-bus voltage based on the judgment result by judging the magnitude relationship between the first half-bus voltage and the voltage required by the first load when both half-bus voltages are less than or equal to the overvoltage protection value. That is, the embodiment of the present application can determine the control amount of the corresponding half-bus voltage based on the magnitude relationship between the first half-bus voltage and the voltage required by the first load, and then accurately compensate for the output duty cycle of the switching device, which is conducive to the implementation of the voltage control strategy.

[0088] Exemplarily, the above-mentioned determination of the control amount of the half-bus voltage based on the judgment result may include: when the first half-bus voltage is less than the voltage required by the first load, determining the control amount of the half-bus voltage as: the difference between the voltage required by the first load and the first half-bus voltage; when the first half-bus voltage is greater than or equal to the voltage required by the first load, determining the control amount of the half-bus voltage to zero.

[0089] It can be understood that when the first half-bus voltage is less than the voltage required by the first load, determining the control amount of the half-bus voltage as the difference between the voltage required by the first load and the first half-bus voltage is beneficial to increasing the output duty cycle of the switching device, and thus beneficial to making the first half-bus voltage greater than or equal to the voltage required by the first load, that is, beneficial to implementing the voltage control strategy.

[0090] When both half-bus voltages are less than or equal to the overvoltage protection value, and the first half-bus voltage is greater than or equal to the voltage required by the first load, it indicates that the two half-bus voltages meet the requirements of the voltage control strategy. At this time, by determining the control amount of the half-bus voltage to zero, the output duty cycle of the switching device can be kept unchanged, thereby realizing the voltage control strategy.

[0091] Exemplarily, the above-mentioned determination of the control quantity of the half-bus voltage based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may also include: determining that the first half-bus voltage is less than or equal to the overvoltage protection value, and the second half-bus voltage is greater than the overvoltage protection value, and determining the control quantity of the half-bus voltage as: the difference between the second half-bus voltage and the overvoltage protection value; the second half-bus voltage represents the other half-bus voltage of the two half-bus voltages excluding the first half-bus voltage.

[0092] Exemplarily, the above-mentioned determination of the control quantity of the half-bus voltage based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may also include: determining that the first half-bus voltage is greater than the overvoltage protection value and the second half-bus voltage is less than or equal to the overvoltage protection value, and determining the control quantity of the half-bus voltage as: the difference between the overvoltage protection value and the first half-bus voltage.

[0093] It can be understood that when the first half-bus voltage is greater than or equal to the overvoltage protection value, it means that the first half-bus voltage does not meet the requirements of the voltage control strategy. At this time, the control amount of the half-bus voltage is determined as the difference between the overvoltage protection value and the half-bus voltage supplying power to the first load, which is beneficial to reducing the output duty cycle of the switching device, and then helps to make the first half-bus voltage less than the overvoltage protection value, that is, it is beneficial to implement the voltage control strategy.

[0094] Exemplarily, the above-mentioned determination of the control quantity of the half-bus voltage based on the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load may also include: determining that both half-bus voltages are greater than the overvoltage protection value, and determining the control quantity of the half-bus voltage as: the difference between the second half-bus voltage and the first half-bus voltage.

[0095] It can be understood that when both half-bus voltages are greater than the overvoltage protection value, the control amount of the half-bus voltage is determined as the difference between the second half-bus voltage and the first half-bus voltage, and control can be performed based on the midpoint balance between the first half-bus voltage and the second half-bus voltage.

[0096] The following combination Figure 7 The process of determining the control amount of the half-bus voltage in the embodiment of the present application is described.

[0097] Reference Figure 7 , V bus_n Represents the first half bus voltage, V bus_p Indicates the second half bus voltage; first determine V bus_n and V bus_p Are they both greater than the overvoltage protection value V lim If yes, then the half bus voltage control quantity V bus_fb Determined to be V bus_p Subtract V bus_n The difference is then used to control the half bus voltage V bus_fb Output to the duty cycle compensation controller 602.

[0098] One of the first half bus voltage and the second half bus voltage is less than or equal to the overvoltage protection value V lim When V bus_p Is it greater than V bus_n If yes, then the half bus voltage control quantity V bus_fb Determined to be V bus_p Subtract V lim The difference is then used to control the half bus voltage V bus_fb Output to the duty cycle compensation controller 602.

[0099] In V bus_p Less than or equal to V bus_n When the half bus voltage control quantity V bus_fb Determined to be V Lim Subtract V bus_n The difference is then used to control the half bus voltage V bus_fb Output to the duty cycle compensation controller 602.

[0100] When the first half bus voltage and the second half bus voltage are both less than or equal to the overvoltage protection value V limWhen V bus_n Is it less than the voltage V required by the first load? Ld1 , the first load is the above load 1; if V bus_n Less than the voltage V required by the first load Ld1 , then the control quantity of half bus voltage V bus_fb Determined to be V Ld1 Subtract V bus_n The difference is then used to control the half bus voltage V bus_fb Output to the duty cycle compensation controller 602.

[0101] In V bus_n Greater than or equal to the voltage V required by the first load Ld1 When the half bus voltage control quantity V bus_fb Determine to be 0, at this time, the output duty cycle compensation amount r approaches 0, then the half bus voltage control amount V bus_fb Output to the duty cycle compensation controller 602.

[0102] The computer program instructions corresponding to a voltage control method in this embodiment can be stored on a storage medium such as a CD, a hard disk, or a USB flash drive. When the computer program instructions corresponding to a voltage control method in the storage medium are read or executed by a control device, any voltage control method in the aforementioned embodiments is implemented.

[0103] Based on the same technical concept as the above embodiment, see Figure 8 , which shows a voltage control device 800 provided in an embodiment of the present application, which may include: a memory 801 and a processor 802; wherein,

[0104] Memory 801, used to store computer programs and data;

[0105] The processor 802 is configured to execute a computer program stored in the memory to implement any one of the voltage control methods in the foregoing embodiments.

[0106] In practical applications, the memory 801 may be a volatile memory, such as RAM; or a non-volatile memory, such as ROM, flash memory, hard disk drive (HDD) or solid-state drive (SSD); or a combination of the above types of memory, and provide instructions and data to the processor 802.

[0107] The processor 802 may be at least one of an ASIC, a DSP, a DSPD, a PLD, an FPGA, a CPU, a controller, a microcontroller, and a microprocessor. It is understood that for different augmented reality cloud platforms, the electronic device used to implement the above processor functions may also be other, and this embodiment of the application does not specifically limit this.

[0108] An embodiment of the present application also provides a household appliance, which includes the above-mentioned voltage control device 800 and a second load; the voltage control device is connected between the AC power supply signal and the second load, and the voltage control device is configured to control the AC power supply signal to supply power to the second load.

[0109] Exemplarily, the second load may be the same as the first load, or the second load may be a load of full bus voltage.

[0110] Exemplarily, the functions or modules included in the apparatus provided in the embodiments of the present application can be used to execute the method described in the above method embodiments. The specific implementation thereof can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0111] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other. For the sake of brevity, this article will not repeat them.

[0112] The methods disclosed in the various method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0113] The features disclosed in the various product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0114] The features disclosed in the various method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0115] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0116] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0117] In addition, all functional units in the embodiments of the present application can be integrated into one processing module, or each unit can be a separate unit, or two or more units can be integrated into one unit; the above-mentioned integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0118] Those skilled in the art will understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiments.

[0119] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A voltage control method, characterized in that: Applied to a power factor correction (PFC) circuit, the PFC circuit includes a three-level converter, and the method includes: Obtaining two half-bus voltages on the DC side of the three-level converter, overvoltage protection values ​​of the two half-bus voltages, and a voltage required by a first load; the first load represents a load whose supply voltage is any one of the two half-bus voltages; determining an output duty cycle compensation amount based on a relationship between the two half-bus voltages, the overvoltage protection value, and a voltage required by the first load; and compensating a current output duty cycle of the switching device of the three-level converter using the output duty cycle compensation amount to obtain a voltage control strategy, wherein the voltage control strategy is configured to compensate the output duty cycle of the switching device of the three-level converter so that a first half-bus voltage is greater than or equal to the voltage required by the first load and each of the two half-bus voltages is less than or equal to the overvoltage protection value; the first half-bus voltage represents a half-bus voltage supplying power to the first load; The two half-bus voltages are controlled according to the voltage control strategy.

2. The method according to claim 1, characterized in that The determining the output duty cycle compensation amount according to the relationship between the two half-bus voltages, the overvoltage protection value, and the voltage required by the first load includes: According to the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load, the control amount of the half-bus voltage is determined; and proportional integral (PI) control is performed on the control amount of the half-bus voltage to obtain the output duty cycle compensation amount.

3. The method according to claim 2, characterized in that The determining the control amount of the half-bus voltage according to the relationship between the two half-bus voltages, the overvoltage protection value, and the voltage required by the first load includes: Determining that both half-bus voltages are less than or equal to the overvoltage protection value, determining a magnitude relationship between the first half-bus voltage and a voltage required by the first load, and obtaining a determination result; The control amount of the half-bus voltage is determined according to the judgment result.

4. The method according to claim 3, characterized in that Determining the control amount of the half-bus voltage according to the judgment result includes: Determining that the first half-bus voltage is less than the voltage required by the first load, and determining the control amount of the half-bus voltage as: the difference between the voltage required by the first load and the first half-bus voltage; It is determined that the first half-bus voltage is greater than or equal to the voltage required by the first load, and the control amount of the half-bus voltage is determined to be zero.

5. The method according to claim 3 or 4, characterized in that The determining the control amount of the half-bus voltage according to the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load further includes: Determine that the first half-bus voltage is less than or equal to the overvoltage protection value, and the second half-bus voltage is greater than the overvoltage protection value, and determine the control quantity of the half-bus voltage as: the difference between the second half-bus voltage and the overvoltage protection value; the second half-bus voltage represents the other half-bus voltage of the two half-bus voltages excluding the first half-bus voltage.

6. The method according to claim 3 or 4, characterized in that The determining the control amount of the half-bus voltage according to the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load further includes: Determine that the first half-bus voltage is greater than the overvoltage protection value, and the second half-bus voltage is less than or equal to the overvoltage protection value, and determine the control quantity of the half-bus voltage as: the difference between the overvoltage protection value and the first half-bus voltage, wherein the second half-bus voltage represents the other half-bus voltage of the two half-bus voltages excluding the first half-bus voltage.

7. The method according to claim 3 or 4, characterized in that The determining the control amount of the half-bus voltage according to the relationship between the two half-bus voltages, the overvoltage protection value and the voltage required by the first load further includes: Determine that both of the two half-bus voltages are greater than the overvoltage protection value, and determine the control quantity of the half-bus voltage as: the difference between the second half-bus voltage and the first half-bus voltage, where the second half-bus voltage represents the other half-bus voltage of the two half-bus voltages excluding the first half-bus voltage.

8. The method according to claim 1, characterized in that The overvoltage protection value is less than or equal to the withstand voltage value of the capacitor on the DC side of the three-level converter.

9. A voltage control device, characterized in that: The device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method according to any one of claims 1 to 8 when executing the program.

10. A household appliance, characterized in that: The household appliance includes the voltage control device according to claim 9 and a second load; the voltage control device is connected between the AC power supply signal and the second load, and the voltage control device is configured to control the AC power supply signal to supply power to the second load.

11. A computer storage medium having one or more programs stored thereon, wherein the one or more programs can be executed by one or more processors to implement the method according to any one of claims 1 to 8.

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